Ten percent of American adults, more than 20 million people, have chronic kidney disease, which in the advanced state of end stage renal disease is most desirably and cost-effectively treated by kidney transplantation. However, 20-30% of transplanted kidneys fail in living recipients by 10 years, owing largely to insufficient monitoring methods. The goal of the proposed research is to improve noninvasive kidney transplant monitoring using a new ultrasound-based imaging method called Viscoelastic Response (VisR) ultrasound.